There are currently a great number of types of mattresses on the market that ensure giving people's bodies beneficial rest, and which also must fulfil the function of giving people proper support, being neither too soft nor too hard. The main varieties are the following:                Wool mattress: currently they are produced very infrequently, because wool has been replaced by new materials. This type of mattress has as a drawback that with use, the wool becomes lumpy and that every two or three years it has to be re-carded so as to restore its consistency. In addition, mattress makers are very scarce nowadays.        Spring mattress: it is made of steel springs that can be bi-conical (the upper and lower turns are bigger than the central ones), or helical (the turns have all got the same diameter), and they are often individually isolated in order to prevent noise. On either side of the springs, the filling-holder is lined with a layer of horsehair, sisal or felt; a cotton, wool or synthetic fibre filling, which in turn are also lined; and finally, the whole assembly is closed into the outer cover. These mattresses are solid and comfortable.        “Multi-elastic” mattresses differ from those of traditional springs in that they have a kind of thick net of metallic thread.        Synthetic latex mattress: a chemical reconstruction of natural latex. These mattresses have a flat surface, and another one full of cells that facilitate air circulation. They are very hygienic, but sensitive to light when they are exposed to it without their covers.        Polyester mattress: the density of polyester used for producing mattresses must not be less than 25 kg/m3. The softness of the foam depends on this density. Since the regulations are not always respected, this type of material has acquired an undeservedly bad reputation. Before buying one of these mattresses, the consumer should insist that the density of the foam rubber should be specified. It should also have a thickness of, at least, 10 cm to be of good quality.        
With the objective of solving the described problems, a new type of mattress has been developed, which is described below.